Starting multiple workspaces at the same time fails because the workspace status changed unexpectedly to stopped

Description of problem:

When starting workspaces with multiple users at the same time, some workspaces do not start with the following error:

The workspace status changed unexpectedly to "Stopped"

Restarting the failed workspaces will start normally.

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. Multiple users pre-logged in and opened the devspaces dashboard
2. Create workspaces at the same time 

Actual results:

Some workspaces don't start

Expected results:

All workspaces start properly

Reproducibility (Always/Intermittent/Only Once):

Almost always

Build Details:

Additional info (Such as Logs, Screenshots, etc):

Changing DWOC `config.workspace.imagePullPolicy` and `config.workspace.progressTimeout` doesn't work

kind: DevWorkspaceOperatorConfig
apiVersion: controller.devfile.io/v1alpha1
metadata:
  name: devworkspace-config
config:
  workspace:
    imagePullPolicy: IfNotPresent
    progressTimeout: '15m'